Braking system



L. E. LA @RIE BRAKING SYSTEM July 5, 1932.

, 1925 2 Sheets-Sheet 1 Original Filed Aug. 12

o o o '0 INVENTOR. LUDGER E. LA BRIE ATTORNEY L. E. LA BRIE July 5, 1932.

BRAKING SYSTEM Original Filed Aug. 12, 1925 2 Sheets-Sheet 2 INVENTOR. LUDGER E.LA BRIE ATTORNEY Patented July 5, 1932 UNITED STATES PATENT OFFICE LUDGER E. LA BRIE, OF SOUTH. BEND, INDIANA, ASSIGNOR TO BENDIX BRAKE COM- PANY, OF SOUTH BEND, INDIANA, A CORPORATION OF ILLINOIS BRAKING SYSTEM Original application filed August 12, 1925, Serial No. 49,736. Divided and this application filed June 20, 1930. Serial No. 462,472.

The present invention is a division -of my pending application Serial No. 49,736, filed August 12, 1925 which has matured into Patent No. 1,781,112 and is made under requirements of the United States Patent Oflice under provision of rule 41.

This invention relates to brakes and is illustrated as embodied in an automobile chassis having front wheel brakes and a transmission brake acting on the rear wheels.

An object of the invention is to provide simple and reliable means for utilizing the transmission brake as a servo device for applying the front brakes, without interfering with its function of retarding movement of the rear wheels through the propeller shaft. An important feature of the invention from this point of view is inproviding means, other than the front brake connections, for limiting the angular movement at the transmission brake which operates those connections. This not only permits carefully proportioning the retarding effects between the rear and front wheels, but also insures that the transmission brake will remain operative even in case of accident of the front brake connections.

Preferably the angular movement at the transmission brake, shown as a movement of a backing plate or similar sup ort carrying the friction means, is limite yieldingly by springs, so that increased pressure on the brake pedal will cause increased angular movement, and consequent increased pressure 5 on the front brakes, as well as increased retarding effect on the rear wheels.

I The transmission brake itself embodies a number of features of novelty, including a 0 novel arrangement of three shoes acting on the propeller shaft, a very simple control arrangement including a shaft supported by the transmission, and other features whichwill be apparent from the following description 45 of one illustrative embodiment of the invention shown in the accompanying drawings, in which: v

Figure 1 is a top plan view of an automobile chassis, showing diagrammatically one posw sible arrangement;

Figure 2 is a vertical section longitudinally of the car through the transmission brake;

Figure 3 1s a vertical section on the line 3--3 of Figure 2 showing the shoes in side ele-.

vation and F1 gure 4 is a vertical section on the line 4-4 of Figure 2 showing the movement-limiting 20. The rear wheels 22 are driven from an engine 24 tlrrough a transmission 26 and propeller shaft 28. Except as further described below, these parts or their equivalents may be of any desired construction.

The'brakes may be applied by any suitable device, a service pedal 30 being shown, and

having one end below its fulcrum forked or slotted to embrace an arm 32 on a vertical shaft 34 having a crank 36 connectedjby a link 38 to an arm 40 extending upwardly from a brake-applying shaft '42.

Shaft 42 is slidably supported at one end by a sleeve44 held by tubular flanges formed on inner and outer spherical shells 46 and 48, held by a spring 50 confined between shell 46 and a stop 52 on the sleeve 44. Shells 46 and 48 embrace a spherical part of a stationary support 54 secured to the transmission 26.

At its opposite end, shaft 42 is flattened and perforated to be swivelled by a vertical pin 56' between approximately semicylindri cal connectors 58 held in a cylindrical bore in the end of a short saft 60 carrying a double cam 62. 7

Cam 62 is arranged to force apart, against the resistance of a return spring 64, a reverse shoe 66 and a servo shoe 68, the servo shoe 68 turning with the drum'70 and forcing against the drum a central shoe 72 to which it is pivotally connected at 74. During the initial movement of shoe 68, shoe 72 is held away from the drum by an auxiliary spring 100 76, insuring smooth and gradual effectiveness of the shoes.

Shoe 66 is anchoredat 78 between the ends of shoe 72, and shoe 72 is anchored at 80 between the ends of shoe 66, shoes66 and 68 preferably being forked to straddle or overlap' the ends of shoe 72. Both anchors 78' and 80 may be carried by a backing plate or other support 82 at the open side of the drum. Drum is shown as secured to and rotating with the propeller shaft 28, while support 82 is provided with a tubular projection 84, sleeved for support on a tubular part 86 of the housing of the transmission 26.

When the brake is applied by depressing the pedal, the support 82 is turned in one direction or the other with the drum, shoes 68 and 72 being effective if the vehicle is moving forward and shoe 66 being effective if the vehicle is moving backward. This angular movement is yieldingly limited by two pairs of springs 88 and 90, embracing arms 92 and 94 secured to the support, and confined between upper and lower brackets 96 carried by frame 10.

After support 82 comes to rest, the friction means shown as including shoes 66, 68 and 72 acts as a transmission brake to retard movement of the rear wheels 22 through the propeller shaft 28 and throu h the differential 1n the rear axle 14, the differential serving to equalize the retarding effect on the two wheels.

The arms 92 and 94 are connected by links 98 to arms 100 on shaft 20, each link 98' projecting through an opening in the corresponding arm and having an adjustable nut 102 or other stop engaging the bottom of the arm. This constitutes an over running connection, so that if the drum 70 is turning in one direction the one arm 100 rocks shaft 20, and if the drum is turning in the opposite direction the other arm 100 rocks the shaft, but in either case the shaft 20 applies the front brakes. If desired, a light antirattle spring 104 ma hold each arm 100 against its stop 102 w en the brakes are not applied.

It is important to note that springs 88 and '90 yield in proportion to the de ression of pedal 30, and. that consequently the pressure on the front brakes, as well as the retarding effect of the transmission brake, is contro led by the pedal. Arm 40 is so formed and so arranged that, when the brakes are on, its joint with link 38 is directly. in a vertical axis passing through the universal joint at the transmission end of shaft 42, so that angular movement of support 82, permitted blyl the universal joints at "opposite ends of s aft 42, does not affect the pressure put on the shaft by depression of the pedal.

While one illustrative embodiment has been described in detail, it is not my intention to limit the scope of the invention to thereof, and comprising, in combination, a

drum facing the transmission, a support on the transmission side of the drum, friction means between the drum and support, and a control shaft for the friction means supported at one end on the transmission and at the other end on the support.

2. A vehicle having a transmission with a power-driven shaft extending rearwardly thereof, and comprising, in combination, a drum on the shaft facing the transmission, friction means within the drum, a control shaft for the. friction means universally supported by the transmission, and an expand- 111g device for the friction means within the drum and universally jointed to the shaft.

3. A vehicle having a transmission with a power-driven shaft extending rearwardly thereof, and comprising, in combination, a brake for the shaft, and a control for applying the brake including a shaft universally supported on the transmission and having a universal joint at the brake end.

4. A vehicle having a transmission with a power-driven shaft extending rearwardly thereof, and comprising, in combination, a brake for the shaft, a control for applying the brake including a shaft universally supported on the transmission and having a universal joint at the brake end, the brake having a limited angular movement, and other retarding means operated by such angular movement.

5. A vehicle having in combination. a transmission, a transmission brake, and a control shaft for applying the brake which is universally supported at one end on the transmission.

In testimony whereof, I have hereunto signed my name.

LUDGER E. LA BRIE.

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